Central Deccan Plateau dry deciduous forests

The Central Deccan Plateau Dry Deciduous Forests [IM0201] make up a large ecoregion that is neither exceptionally species-rich nor high in numbers of endemic species. But the ecoregion still contains about 20 percent of its natural habitat as several large blocks, some of which exceed 5,000 km2. In a region characterized by a high human population density and the presence of several large vertebrate species, the presence of large natural habitat areas is both unusual and important. These large habitat blocks have been recognized as high-priority landscapes for a long-term tiger conservation strategy (Wikramanayake et al. 1999); therefore, the ecoregion makes an important contribution to a regional tiger conservation strategy.

Scientific Code

(IM0201)

Ecoregion Category

Indo-Malayan

Size

92,700 square miles

Status

Critical/Endangered

Habitats

Description Location and General DescriptionThis ecoregion represents the Hardwickia-dominated woodlands in the central Deccan Plateau, a vegetation type that is distinct from the teak (Tectona grandis) or sal (Shorea robusta) dominated dry forests that cover most of the Deccan Plateau. The ecoregion extends across the central Indian states of Madhya Pradesh, Maharashtra, Karnataka, and Andhra Pradesh. It includes the western extent of the Satpura Range of hills within the northern extent. The Godavari River, which originates in the Western Ghats, crosses the ecoregion as it traverses the Deccan Plateau.

Structurally, the dry forests in this ecoregion have an upper canopy at 15-25 m and an understory at 10-15 m. Lianas drape the trees in mature forests, but the undergrowth is sparse (Puri at al. 1989). The characteristic tree association is Hardwickia binata-Albizia amara woodland with Tectona grandis, Boswellia serrata, Lannea coromandelica, Anogeissus latifolia, Albizia lebbek, Lagerstroemia parvifolia, Diospyros tomentosa, and Acacia catechu in the northern areas and Pterocarpus santalinus, P. marsupium, Chyloroxylon swietenia, Terminalia chebula, T. tomentosa, Albizia lebbek, and Dalbergia latifolia in the southern areas of the ecoregion (Puri et al. 1989). The Nagarjunasagar-Srisailam Tiger Reserve in Andhra Pradesh represents the typical habitat in this ecoregion. Several sacred groves containing evergreen forests in the state of Andhra Pradesh make an important contribution to conservation and to the ecoregion's diversity.

Biodiversity FeaturesAlthough not exceptional in terms of endemism and diversity, this ecoregion harbors several of India's large, threatened vertebrates such as the tiger (Panthera tigris), wild buffalo (Bubalus arnee), wild dog (Cuon alpinus), sloth bear (Melursus ursinus), chousingha (Tetracerus quadricornis), gaur (Bos gaurus), blackbuck (Antilope cervicapra), and chinkara (Gazella bennettii) (IUCN 2000). Significantly, the large habitat blocks provide an opportunity to conserve these wide-ranging species whose populations are fast declining throughout most of their ranges because of habitat loss and hunting.

The known mammal fauna in the ecoregion includes eighty-two species, but none are endemic to the ecoregion. In addition to the larger, threatened mammal species mentioned earlier, the ecoregion also harbors the threatened Malabar squirrel (Ratufa indica) (IUCN 2000).

The bird fauna is richer, with almost 300 species, of which one, the globally threatened Jerdon's courser (Rhinoptilus bitorquatus), is a near-endemic species (table 1). This species was rediscovered in 1986, after the last record in 1900 (Grimmet et al. 1998). The small distribution range of the only known population of this rare species extends across this ecoregion and the neighboring Deccan Thorn Scrub Forests [IM1301].

Table 1. Endemic and Near-Endemic Bird Species.

Family Common Name Species Name Glareolidae Jerdon's courser Rhinoptilus bitorquatus

An asterisk signifies that the species' range is limited to this ecoregion.

Current StatusAbout 80 percent of the natural habitat in this ecoregion has already been lost, but the remaining habitat includes several blocks that exceed 5,000 km2. These large habitat blocks along the southern and eastern boundaries of the ecoregion have been the basis for the high-priority TCU (Wikramanayake at al. 1999).

The sixteen protected areas in this ecoregion cover almost 3 percent of its area. The Nagarjunasagar Tiger Reserve, at more than 3,500 km2, is one of the largest and most important protected areas in this bioregion. Recent ecodevelopment and habitat restoration efforts in this tiger reserve have proved successful in bringing back the dwindling tiger population.

Ecoregion numbers of protected areas that overlap with additional ecoregions are listed in brackets.

Types and Severity of ThreatsThe remaining natural habitat is now under severe threat from conversion to cash crop plantations, excessive fuelwood collection, and overgrazing by cattle. The habitat loss results in a decreasing prey base for tigers that then turn to the livestock that are grazed around and within the forests. Retaliation by the local people against these depredations has affected tiger populations. But although these degradation threats nibble away at the intact forests, large hydroelectric projects present more severe, high-impact threats (Davis et al. 1995).

As the tribal people in the area shift from a subsistence lifestyle to more material lifestyles and the populations grow, there are inevitable conflicts with diminishing resources. These conflicts must be addressed early with resource and land-use plans.

The ecoregion's conservation status was changed from vulnerable to endangered because of the projected impacts of the human population on the remaining forest blocks

The Naxalite conflict in northeast India is also being funded by proceeds from rhinoceros, tiger, and elephant poaching.

Justification of Ecoregion DelineationIn a previous analysis of conservation units, Rodgers and Panwar (1988), and subsequently MacKinnon (1997), divided the Deccan Peninsula into five biotic provinces.

The Hardwickia-dominated woodlands represented by this ecoregion extend across the Deccan Plateau South (6A) and Central Plateau (6B) biotic provinces identified by Rodgers and Panwar (1988). However, both provinces also include other vegetation types. In keeping with our definition of an ecoregion (i.e., an ecosystem of regional extent) and following our rules for ecoregion delineation (representing distinct vegetation types of regional extent in separate ecoregions), we placed the Hardwickia dry forests into the Central Deccan Plateau Dry Deciduous Forests [IM0201]. We used MacKinnon's (1997) map of the original vegetation to delineate the ecoregion boundaries.

ReferencesReferences for this ecoregion are currently consolidated in one document for the entire Indo-Pacific realm.Indo-Pacific Reference List